Gather and measure all the ingredients for your gluten-free apple muffins.
Preheat the oven to 350°F and line a muffin tin with muffin liners.
In a large bowl, combine the applesauce, melted butter, and eggs.
Stir in the sugar, salt, and vanilla extract.
Add the GF flour, baking powder, baking soda, and cinnamon. Mix until the batter is fully combined.
Divide the apple muffin batter evenly into the prepared muffin tin.
To make the brown sugar crumb topping, combine the brown sugar, granulated sugar, gluten-free flour, and cinnamon in a small bowl.
Stir in the melted butter until the mixture becomes crumbly.
Sprinkle about a tablespoon of the brown sugar crumble over each muffin.
Bake for 20 minutes, or until a toothpick inserted into the center comes out clean.
Let the muffins cool on a cooling rack before serving. Enjoy!